Performance Optimization And Experimental Research Of Oil And Casing Gas Seal Testing Tools

In order to ensure the leakproofness of oil casing of gas storage wells and high pressure gas wells,the special screwed nipple is more and more widely applied in well entrance tubular column of gas storage wells and high pressure gas wells,as a result,gas seal testing technology has been gradually promoted.Oil casing gas seal testing technology,based on the operating pressure of tested wells and oil casing pressure-bearing levels,calculates the pressure tested,tests couplings of each well entrance tubular column before they enter into the wells,ensures the overall leakproofness of tubular column and ensures the service life and safety operation of the wells.The testing apparatus of oil casing in gas seal,key device of the gas seal testing technology,will directly affect the gas testing effect and construction cycle by its performance.The sealing effect,pressure-bearing capacity and service life of oil casing gas seal testing apparatus have become the key problems and technical difficulties of domestication.Through the finite element analysis and optimization to improve the performance of the products is the common method used by scholars in related field.However,only few bibliography and reports relate to optimization of performance in gas seal testing apparatus.This paper has applied the combination of theoretical calculation,simulation optimization and experiments,analyzed mechanical deformation regularity of rubber sleeve in gas seal testing apparatus in different materials and parameters;compared and chosen the best material and structure size of rubber sleeve to achieve products with good sealing effect,pressure-bearing capacity and service life.The main research work in this paper is as follow.(1)Theoretical calculation method has been adopted and mature compression type packer design principle has been used for reference to calculate key size parameters of gas seal testing apparatus.According to the calculation results,the optimal scope for the parameters will have been determined with the scope working as the design basis for the finite element simulation model parameters.(2)On the basis of referring to bibliography,choice of Yeoh model can get a relatively precise behavior description,according to the existing unit experimental conditions and simulation results of constitutive model.The uniaxial tensile and uniaxial compression unit experiment should be completed to get the material parameters of the domestic ordinary rubber A and the import hydrogenated nitrile rubber B,through data analyses,together with comparison with Rubber C in choice of related bibliography reference.(3)3-1/2 rubber sleeve of oil casing testing apparatus has been used as the research object to describe deformation regularity of rubber sleeve in its operation process with the combination of the results of numerical simulation.Finite element simulation has been operated by the choice of three different rubber materials,five groups height,six groups thickness,four groups unilateral clearance value.Through finite element simulation analyses,it has been found that rubber sleeve with material B and Rji = 20mm,Rjo = 35mm,H ?90mm,? ? 3mm has good sealing effect,pressure-bearing capacity and service life.(4)Gas seal testing apparatus pressure-bearing performance experimental platform and method have been designed,experimental platform has been set up and experimental test has been completed in 3-1/2in gas seal testing apparatus rubber sleeve under seven kinds of working conditions.Test study indicates that when center tube pressure Pz = 20MPa,the annular space which formed by the rubber and casing pipe can seal the largest pressure Ph = 35MPa.The seal extreme pressure is 1.5 times higher than axial load,and under this condition the sealing effect is good,the maximum pressure drop percentage is less than 5%,the pressure drop conform to the requirement which has good bearing capacity.Verify the validity of the finite element analysis and optimization design.(5)On the basis of computer simulation analysis and experimental research,3-1/2 gas seal testing apparatus has been designed and manufactured.The whole size experimental result has shown good sealing effect with no leakage,quick rubber sleeve rebounce,more than 100 times of fatigue endurance in rubber sleeve and protective jacket,which has met the performance requirements in gas seal technology.Through the study of this article,3-1/2 gas seal testing apparatus with good performance has been accquired.The analysis results and experimental data in this paper can be used as design basis,which has played the role of reference significance to the design of other series products.The design ideas,methods and experimental platform can be applied to other specifications of gas seal testing apparatus.The improvement of performance of the gas seal testing apparatus has broken the monopoly of foreign products,improved the domestic design and research ability in gas seal testing apparatus and provided apparatus support for the implementation of gas seal testing technology.In addition,the domestication of the product has also reduced the production cost,with certain economic significance.